Optimized T1- and T2-weighted volumetric brain imaging as a diagnostic tool in very preterm neonates

Abstract

Background T1-and T 2 -W MR sequences used for obtaining diagnostic information and morphometric measurements in the neonatal brain are frequently acquired using different imaging protocols. Optimizing one protocol for obtaining both kinds of information is valuable. Objective To determine whether high-resolution T1-and T 2 -W volumetric sequences optimized for preterm brain imaging could provide both diagnostic and morphometric value. Materials and methods Thirty preterm neonates born between 24 and 32 weeks' gestational age were scanned during the first 2 weeks after birth. T1-and T 2 -W highresolution sequences were optimized in terms of signal-tonoise ratio, contrast-to-noise ratio and scan time and compared to conventional spin-echo-based sequences. Results No differences were found between conventional and high-resolution T 1 -W sequences for diagnostic confidence, image quality and motion artifacts. A preference for conventional over high-resolution T 2 -W sequences for image quality was observed. High-resolution T1 images provided better delineation of thalamic myelination and the superior temporal sulcus. No differences were found for detection of myelination and sulcation using conventional and high-resolution T 2 -W images. Conclusion High-resolution T1-and T 2 -W volumetric sequences can be used in clinical MRI in the very preterm brain to provide both diagnostic and morphometric information.R. Nossin-Manor (*)

Three-Dimensional Magnetic Resonance Fingerprinting in Neonates

“…30 The T1 (WM, 2636-2890 milliseconds; GM, 2113-2372 milliseconds) and T2 values (WM, 163-206 milliseconds; GM, 90-136 milliseconds) of preterm neonates of our study were consistent with a previous study that found T1 (WM, 2836-3045 milliseconds; GM, 1975-2196 milliseconds) and T2 values (WM, 216-255 milliseconds; GM, 153-167 milliseconds) for preterm neonates using spin echo-based sequences. 18 Gray matter also showed lower T1 and T2 values compared with WM in previous studies. 9,18,25 In preterm neonates, quantitative tissue characteristics can be used to differentiate brain regions.…”

“…18 Gray matter also showed lower T1 and T2 values compared with WM in previous studies. 9,18,25 In preterm neonates, quantitative tissue characteristics can be used to differentiate brain regions. Accordingly, a previous study showed that diffusion tensor imaging parameters had sufficient sensitivity and specificity to differentiate brain regions such as the globus pallidus or putamen in preterm neonates.…”

“…Whereas WM T1 and T2 values after infancy are below 1800 milliseconds and 160 milliseconds, respectively, 6 the WM of neonates have higher T1 and T2 values. 18 A proper MRF dictionary for neonatal brain imaging will enhance the differentiation of structures and changes according to maturation. Second, minimizing scanning times is essential for this young population.…”

Quantitative MRI in the very preterm brain: Assessing tissue organization and myelination using magnetization transfer, diffusion tensor and T1 imaging

“…T 1 relaxometry measurements reported for neonates at term, preterm infants at term equivalent age and for preterm brain at birth showed lower T 1 values in GM structures compared to non-myelinated WM (Jones et al, 2004;Nossin-Manor et al, 2011;Williams et al, 2005). Furthermore, a study in healthy term-born infants from 3 to 11 months of age demonstrated lower T 1 values in GM structures compared to unmyelinated WM and in myelinated WM compared to GM structures (Deoni et al, 2011).…”

Comparison between T2 Relaxation Time and Storage Modulus for Agarose Gel

“…It is affected by the presence of static internal fields, usually from protons of large molecules. T 2 values have been found to be an important diagnostic tool for assessing various disease pathologies [1].…”